f**k man that sucks balls sorry to hear. Unfortunately it will be a battle for him to pay anything. As you did not have a road worthy on purchase. And with the law the only way you can win this is if you actually asked him if the car had any chasis damage and he said no. Thaw decieving. But if you didn't ask it's more of a case of buyer beware. By what you said you didn't get it inspection done when purchased soni think you will just have to suck up the losses. Live and learn.